1.root out：根除

It is more difficult to root out a bad habit than build a good one.根除恶习比培养一个好习惯困难得多。

混淆短语：pull up one's roots：从久居地移居他乡

The civil war had forced many people to pull up their roots.内战迫使许多人不得不移居他乡。

2.root and branch：彻底地

Many people strongly oppose the idea of abolishing death penalty root and branch.许多人强烈反对彻底废除死刑的想法。

3.rub off：擦掉

He rubbed the lip print off his face.他将脸上的唇印擦掉了。

替换短语：rub out：擦掉

He rubbed out the lip print on his face.他将脸上的唇印擦掉了。